I guess you're thinking of this case?
I think studies going that disastrously wrong are pretty rare, but it's certainly not going to be any fun; the whole point of the study is to find out what kinds of nasty side effects the drug has so it's quite probable to make you ill to some extent.
On the other hand, someone does have to do it or we wouldn't get any new medicines, so I suppose it is a relatively worthwhile thing to do. Becoming a human guinea pig isn't ever going to be a way to make a decent living though.
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